The present invention relates to a computer, or more in particular to a computer capable of restoring an operating system to the status at an arbitrary past time point. Also, the present invention relates to a computer network system connected with a computer having the above-mentioned function and a recording medium having recorded therein a computer program for causing a multipurpose computer to have the above-mentioned function.
When writing the data used by the computer such as an OS (operating system), an application program file, or a data file, the operating system file storing the data (OS, application file, data file, etc.) is rewritten. In a subsequent data read operation, the corresponding data are read from the operating system file thus rewritten, and therefore the operating system file in the latest status is always used.
In a self-maintenance system of a computer, on the other hand, the contents of the operating system file described above are stored in a backup area as backup data. In the case where a fault is found in a given data by a self-diagnosis or in the case where the computer is infected by a virus, the faulty data is rewritten with the data stored in the backup area, thereby making immediate repair possible.
In recent years, with the improvement in personal computer performance, the use of the client/server system has extended. In the client/server system, an operating error by the user or a simple error in setting an environment is liable to develop a trouble affecting the whole network system. In such a case, the maintenance work itself becomes impossible or even a system down situation may occur before successful dissolution of the trouble. The chance of such adversity increases with the number of computers connected to the network, and therefore with the increase in the size of the network system, the resulting economic loss is not negligible. For a network system such as a client/sever system, therefore, as compared with a stand-alone computer used in an isolated situation, the self-maintenance assumes a greater importance.
Further, in a network system such as a client/server system comprising a plurality of computers used as clients and servers, the infection by a computer virus has recently posed a serious problem. Specifically, once any one of a plurality of computers making up a client/server system is infected with a computer virus, all the clients and servers are infected through the network, often leading to a serious loss. Thus, efficient system maintenance is crucial for graceful operation of a client/server system. This is also the case with a stand-alone computer.
In view of this situation, it is common practice to perform the backup work or specifically, the work of storing a copy of data (application file, data file, etc.) used by each computer in the form of backup data as part of the maintenance work of both individual computers of the client/server system and the stand-alone computers. The storage of the backup data and the execution of the self-maintenance permits each computer to be immediately repaired when some data becomes faulty or infected by a computer virus.
The hardware, OS, and the application software of the computer have recently increased in size and become complicated to such an extent that the time required for the self-maintenance has lengthened considerably. Further, in view of the increasing chance for organizations to use the computer for their business activities, using the above-mentioned self-maintenance in batch fashion by diagnosing the computer over the whole period from the starting point to the ending point of use thereof consumes a great amount of time and may cause a wasteful time consumption by the unnecessary diagnosis of parts requiring no repair.
An object of the present invention is to provide a computer which can be restored to the status thereof at an arbitrary time point including the initial time point by monitoring the write operation of the hardware, firmware, and software.
Another object of the invention is to provide a computer network system connected with computers having the function described above.
Still another object of the invention is to provide a recording medium having recorded therein a computer program for causing a multipurpose computer to have the function described above.
In short, according to the present invention, there is provided a stand-alone computer or a computer connected to a computer network system, in which the operation of writing into an operating system file storing data of hardware, firmware or software is monitored, an
d whenever a write operation is executed, the old data replaced by the write operation and the history thereof are stored so that the status at an arbitrary time point including the initial status can be restored based on the two types of data.
According to a first aspect of the invention, there is provided a computer, in which in the case where the data used for the operation of the computer is replaced by writing update data, the particular update data, the updated data replaced by the update data, and the non-updated data not yet replaced by the update data are all stored, and in response to an instruction to restore the initial status, the update data is discarded, while in response to an instruction to restore the status at a designated arbitrary time point, the update data stored after the designated time point is discarded, and in response to an instruction to update the data, the updated data is replaced by the corresponding update data. In this way, the status at an arbitrary time point including the initial status can be easily restored.
According to a second aspect of the invention, there is provided a computer, in which in the case where the data used for the operation of the computer is replaced by writing update data, the particular update data and the history information thereof are stored independently of the data to be replaced by the update data, and in response to an instruction to restore the initial status, the update data is discarded, while in response to an instruction to restore the status at a designated arbitrary time point, the update data stored after the designated time point is discarded with reference to the history information, and in response to an instruction to update the data, the non-updated data is replaced by the corresponding update data. In this way, the status at an arbitrary time point including the initial status can be easily restored.
According to a third aspect of the invention, there is provided a computer, in which, in the case where the data used for the operation of a computer is replaced by writing update data, the particular updated data and the history information thereof are stored independently of the update data. In response to an instruction to restore the initial status, the update data is replaced by the corresponding updated data, while in response to an instruction to restore the status at a designated arbitrary time point, the update data is replaced by the corresponding updated data stored after the designated time point with reference to the history information, and the history information after the designated time point and the corresponding updated data are discarded, and in response to update the data, the updated data and the history information thereof are discarded. As a result, the status at an arbitrary time point including the initial status can be easily restored.
According to a fourth aspect of the invention, there is provided a computer network system, in which, in the case where the data used for the operation of the computer to be monitored is replaced by writing the update data, the update data and the history information thereof are stored in a storage medium different from the storage medium for storing the data to be replaced by the update data. In response to an instruction to restore the initial status, the update data is discarded, while in response to an instruction to restore the status at a designated arbitrary time point, the update data stored after the designated time point is discarded with reference to the history information, and in response to an instruction to update the data, the non-updated data is replaced by the update data. As a result, the status of the computer to be monitored can be easily restored to the status at an arbitrary time point including the initial status.
According to a fifth aspect of the invention, there is provided a computer network system, in which, in the case where the data used for the operation of a computer to be monitored is replaced by writing update data, the updated data and the history information thereof are stored in a storage medium different from the storage medium for the update data, and in response to an instruction to restore the initial status, the update data is replaced by the corresponding updated data, while in response to an instruction to restore the status at a designated arbitrary time point, the update data is replaced by the updated data stored after the designated time point with reference to the history information, and the history information after the designated time point and the corresponding updated data are discarded. In response to an instruction to update the data, the updated data and the history information thereof are discarded. As a result, the status at an arbitrary time point including the initial status of a computer to be monitored can be easily restored.
According to sixth and seventh aspects of the invention, there is provided a recording medium having stored therein a computer program for performing the functions described above. In the case where the computer program recorded in the recording medium according to the sixth aspect of the invention is read by a multipurpose computer, the computer according to the second aspect of the invention described above is realized. Also, in the case where each program code constituting the computer program recorded in the recording medium according to the sixth aspect of the invention is read distributively by a plurality of multipurpose computers interconnected by a network system, the computer network system according to the fourth aspect of the invention described above is realized. In the case where the computer program recorded in the recording medium according to the seventh aspect of the invention is read by a multipurpose computer, on the other hand, the computer according to the third aspect of the invention described above is realized. Further, in the case where each program code constituting the computer program recorded in the recording medium according to the seventh aspect of the invention is read distributively by a plurality of multipurpose computers interconnected by a network system, the computer network system according to the fifth aspect of the invention described above is realized.